Cardiology's archives

Regarding the mechanism of action of AAP10, it was assumed that AAP10 increases cellular coupling because an enhancement of dispersion normally is ascribed to a reduction in cellular coupling and vice versa. The present study provides more evidence for this mechanism of action because it was possible to demonstrate a reduction in coupling time in […]

DISCUSSION Antiarrhythmic peptides were described for the first time in 1980 by Aonuma and colleagues . These peptides were found to enhance synchronization in embryonic chick heart cell aggregates and to suppress aconitine and CaCl2-induced arrhythmias in mice in vivo. However, the mechanism of action remained unclear. After Argentieri and coworkers reported that the natural […]

In additional experiments the spatial structure of AAP10 was clarified using Fourier transformation NMR spectra (1H-NMR, 13C-NMR in D2O or DMSO at 25°C and 40°C). With these investigations it was possible to define the peaks identifying carbon atoms in the molecule and the various hydrogens. A chemical shift was found of the OH moiety of […]

The SDS-PAGE containing connexin 43 is shown in Figure 5. There was a twofold increase in radioactivity compared with the supernatant, which was not different from background activity. In the next step of the further purification of the connexins, ie, of con-nexin 43, radioactivity was lost. Finally, connexin 43 was found, but no 14C-labelled AAP10 […]

A question arises as to the possible clinical significance of cardiac ICa,L block by flecainide. Despite its efficacy in the treatment of some arrhythmias, the results of the Cardiac Arrhythmia Suppression Trial (CAST) showed that flecainide is associated with an increased patient mortality rate . The exact reason for this is unknown, but it may […]

RESULTS AAP10 and natural AAP reduced the dispersion of the epicardial ARIs, meaning that local differences in ARI duration were reduced by the peptide, as shown in Figure 1. It became obvious that with both peptides the percentage of ARI durations within the ±5 ms interval around the mean ARI was increased in a concentration-dependent […]